This invention relates to the field of dish antennas. More particularly, it relates to construction of the dishes for such antennas.
Antennas for receiving electromagnetic signals, such as television signals transmitted from satellites, customarily are of the general configuration of a dish comprising a portion of a paraboloid. This configuration provides for the reflection and focusing of received signals onto a detecting element placed in front of the surface of the dish.
Numerous approaches of construction of such apparatus have been developed. These include structures made out of sheet metal and spun to the parabolic configuration or fabricated from a plurality of wedge-shaped pieces of sheet metal having simple curves and fastened together to form a dish approximating a paraboloid. Additionally, such dishes have been formed out of glass fiber reinforced resin and other synthetic materials. All of these configurations have functional to greater or lesser degrees of satisfaction, but all of them have the disadvantages of undesirable weight and windage, or air resistance.
Recently, such antenna dishes have also been fabricated out of a framework having a plurality of ribs with a metallic signalreflecting mesh filling the spaces between the ribs. Because the mesh provides substantially no structural strength or rigidity it has generally been necessary to provide truss-like supports for the ribs to establish sufficient rigidity for the dish. Additionally, the numerous components comprising such antenna dishes and their ribs and supporting members has generally required extensive assembly and set up time and the use of a large number of fasteners and other components. While these structures have reduced the windage of the antenna dishes, they frequently have remained heavier than desirable, increasing the expense and difficulty of shipping these structures to installation sites.